random effects

Random effects are factors in statistical models that account for variation across groups or categories that are not directly measured but are still important. For example, if you're studying student test scores across different schools, the specific qualities of each school (like teaching style or resources) can influence scores. These school-specific influences are considered random effects—they capture the inherent differences between groups, allowing us to better understand variability in the data without modeling each group perfectly. This approach helps in making more accurate generalizations across a wider population.